A wiring board in which thin conductive wires are formed on a substrate has been widely used as a member such as a transparent electrode, an electromagnetic shield, or a touch panel in various electronic devices. Particularly, there is a rapidly increasing demand for touch panels of various display elements including information communication devices such as mobile phones, and a wiring board using a transparent substrate has become an important member.
On the other hand, as a circuit board provided with wires, a circuit board which is produced by forming a pattern using a conductive ink containing conductive particles such as, for example, silver, through a screen printing method, and performing a heating treatment thereon at a relatively low temperature of about 150° C., thereby forming a wiring pattern has been disclosed. It has also been disclosed that wires having a wire width of about 50 μm to 70 μm can be formed and thus the circuit board can be applied to the manufacturing of touch panels (refer to Patent Document 1).
However, in recent wiring boards used as touch panels or the like as described above, a wire width of about 50 μm is insufficient for wires, and for example, there is a demand for the formation of thin wires having a fine wire width of 20 μm or less. In the method disclosed in Patent Document 1, it is difficult to form such thin conductive wires, and the method would need to rely on an etching method. However, in a case of applying an etching method, the manufacturing process becomes complex, and an additional process such as wastewater disposal is necessary. Therefore, there is a problem in that the manufacturing method of the wiring board becomes complex.